the region isn't developed much…
if they join China in about fifty or a hundred years — that will be for their own benefit…
however they might not need that with their current lifestyle…

The relations between Mongolia and China have been typically strained for a number of years and only recently have shown some signs of thawing up. But distrust still remains.

You can read it up here.

And no, cultural exchanges have been very little, mostly because Mongolian minorities of China sympathize with Mongolia and reject Chinese occupation of a part of Mongolia.

Mongol is one of the 56 Chinese tribes, Outer Mongolia or Mongolia went independent back in the 60s because of the then Soviet's interference and the stupidity of Mao. Soviet had been giving Mongolia a lot of aid until 1990 when the Soviet was broken up themselves. Nowadays Mongolia is making a great efforts to improve ties with China. Who knows, may be one day they'ld like to rejoin the Chinese family.